Gustaf grondal



UNITED STATES PATENT OFFICE.

eusrar ononnan, or munsnomu, swnnnn, assronon 'ro .a s. nonsx s'raan, or

'rnonnnrnm, nonwar.

MANUFACTURE OF IRON SPONGE.

No Drawing.

To all whom it may concern:

Be it known that I, Gus'rar Gnonnan, a subject of the King of Sweden, residing at Djursholm, Sweden, have invented certain new and useful Improvements in the- Manufacture'of Iron Sponge; and I do hereby declare the following to be a full, clear, and exact description of th nvention, such as" will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to the manufacture of iron sponge by the reduction of iron ore andhas for its object a method of treat ing the obtained product so as to prevent its oxidation.

In the manufacture of the product known as iron on by the reduction of iron .ore it is dlfiicu t to efi'ect the cooling of the product in an eflicient manner and to prevent it from being oxidized.

To avoid these difliculties the iron spon has for instance been introduced into gastight vessels where it has been left until cooled or the sponge has been passed over cooled surfaces whereby it has been cooled down before it is subjected to the action of the air. These known processes are however both connected with great drawbacks. Thus according to the firstnamed process the cooling takes place very slowly through the mass, which during the treatment will coalesce into a quite solid mass. Accordilflf? to the other method the cooling will be e cient only when the product is in a finely divided state. This however is usually not the case because a formation of lumps duiin% the reaction could hardly be avoided.

he present invention now has for its object a simple and eflicient method of treating the reduced ore for the purpose of cooling the same and according to which it is of no consequence whether the product is in a finely divided condition or in'the form of lumps.

The invention is based u on the observation that iron spon in a ct condition is not oxidized'when p unged into water from which certain substances such as carbonic acid and bicarbonates contained in ordinary water have been removed or neutralized re spectively.

Specification of Letters Patent.

water which has been previou Patented Nov. 18, 1919.

Application filed January 22, 1918. Serial No. 218,246.

According to this invention the hot product of reduction is introduced into water which previously has been subjected to a boiling process and cooled or to which has been added an alkaline substance such as milk of lime or the like. The desired result may, for instance, be attained by the use of water containing about 0.15 per cent. of Ca (OH),. The iron sponge is refer- .ably introduced into the water directly from the reduction furnace and at the reduction tem erature. Special care must be taken that t 6 water is kept at a comparatively low tem erature for instance about 20 C. It has on found that satisfactory results are obtained even when the temperature of the water rises to about 30 and 40 C. after quenching, but it is preferred to maintain a somewhat lower temperature.

Claims:

-1. In the manufacture of iron sponge by the reduction of iron ore the method which consists in introduci the hot iron sponge obtained by the reduction process into water which has been previously treated in such manner as to remove free carbonic acid from the same. 2. The process which consists in introducmg hot iron spong'e into water previously boiled.

3. The method of preventing the oxidation of iron sponge, which comprises introducing the Riga while but into water contaming no carbonic acid.

4. In the manufacture of iron sponge b the reduction of iron ore the method whic consists in introducin obtained by the re action y treated in such manner as to remove free carboni acid from' the same, the quantity and temperature of the water being controlled in such manner that the temperature of the water is maintained below 50 C.

In testimony that I claim the foregoing as my invention, I have si ed my name in presence of two subscribing witnesses.

. GUSTAF GRUNDAL. Witnesses:

V. Honno'ron,

L. hummus.

the hot iron sponge process into. s 

